Norbert Wolnomiejski and Irena Grygiel
Sea Fisheries Institute, Research Station, Pl. Słowiański 11, 72-600 Świnoujście, Poland

Key words: Baltic estuary, feeding conditions, food of bream.

Abstract.
The diet of the smallest bream specimens (up to 9 cm l.t.) was dominated by zooplankton (about 70 % of food mass) and Ostracoda. Medium-sized specimens (10-19 cm l.t.) consumed zooplankton, Ostracoda, but also Chironomus larvae. The main diet component of fish longer than 19 cm l.t. was Chironomus plumosus larvae. On average, Chironomus larvae constituted 96% of the food mass consumed by bream from the commercially exploited stock (over 35 cm l.t.). The magnitude of the Chironomus larvae consumption index depended on their biomass in the benthos. The benthos of the coastal area played an accessory role in the diet of large common bream. The consumption index was, on average, two-fold higher during the vegetation season than outside of this period.